Tab Control Underline Position

src/MahApps.Metro.Samples/MahApps.Metro.Demo/ExampleViews/TabControlExamples.xaml.cs

@@ -1,4 +1,6 @@
-using System.Windows.Controls;
+using System;
+using System.Collections;
+using System.Windows.Controls;
 using MahApps.Metro.Controls;
 
 namespace MetroDemo.ExampleViews
@@ -12,13 +14,15 @@ public partial class TabControlExamples : UserControl
     {
         public TabControlExamples()
         {
-            InitializeComponent();
+            this.InitializeComponent();
         }
 
         private void MetroTabControl_TabItemClosingEvent(object sender, BaseMetroTabControl.TabItemClosingEventArgs e)
         {
             if (e.ClosingTabItem.Header.ToString().StartsWith("sizes"))
+            {
                 e.Cancel = true;
+            }
         }
 
         private void TextBlock_OnLoaded(object sender, RoutedEventArgs e)
@@ -28,4 +32,16 @@ private void TextBlock_OnLoaded(object sender, RoutedEventArgs e)
             textBlock.SetCurrentValue(TextBlock.TextProperty, (int.Parse(textBlock.Text) + 1).ToString());
         }
     }
-}
+
+    public static class DockHelper
+    {
+        public static IEnumerable GetDockValues()
+        {
+            yield return null;
+            foreach (var dockValue in Enum.GetValues(typeof(Dock)))
+            {
+                yield return dockValue;
+            }
+        }
+    }
+}

src/MahApps.Metro/Controls/Helper/TabControlHelper.cs

@@ -21,7 +21,7 @@ public enum UnderlinedType
     public static class TabControlHelper
     {
         /// Sets the Style and Template property to null.
-        /// 
+        ///
         /// Removing a TabItem in code behind can produce such nasty output
         /// System.Windows.Data Warning: 4 : Cannot find source for binding with reference 'RelativeSource FindAncestor, AncestorType='System.Windows.Controls.TabControl', AncestorLevel='1''. BindingExpression:Path=Background; DataItem=null; target element is 'TabItem' (Name=''); target property is 'Background' (type 'Brush')
         /// or
@@ -270,5 +270,29 @@ public static void SetTransition(DependencyObject obj, TransitionType value)
         {
             obj.SetValue(TransitionProperty, value);
         }
+
+
+
+        /// <summary>
+        /// Defines the position of the <see cref="TabItem"/> Underline
+        /// </summary>
+
+        public static readonly DependencyProperty UnderlinePlacementProperty =
+            DependencyProperty.RegisterAttached("UnderlinePlacement",
+                                                typeof(Dock?),
+                                                typeof(TabControlHelper),
+                                                new PropertyMetadata(null));
+
+        [Category(AppName.MahApps)]
+        [AttachedPropertyBrowsableForType(typeof(TabControl))]
+        public static Dock? GetUnderlinePlacement(UIElement element)
+        {
+            return (Dock?)element.GetValue(UnderlinePlacementProperty);
+        }
+
+        public static void SetUnderlinePlacement(UIElement element, Dock? value)
+        {
+            element.SetValue(UnderlinePlacementProperty, value);
+        }
     }
 }

src/MahApps.Metro/Styles/Controls.AnimatedSingleRowTabControl.xaml

@@ -290,6 +290,7 @@
             <Trigger Property="TabStripPlacement" Value="Right">
                 <Setter Property="Template" Value="{StaticResource VerticalAnimatedSingleRowTabControl}" />
             </Trigger>
+
         </Style.Triggers>
     </Style>
 </ResourceDictionary>